1. Field of the Invention
This invention relates to the extraction of magnetizable metallic particles from liquids such as engine oil and other lubricating liquids, including fluids of various types and particulate matter flowing in a stream, e.g., such as grain and grain flakes, and particularly to a magnetic filter strap embodying multiple permanent magnets one pole of each of which is adapted to lie contiguously, or substantially so, against the exterior wall surface of a container through which the engine oil or other liquid, fluid, or particulate matter, flows through the magnetic field of the permanent magnets, or is otherwise contained.
2. Description of the Prior Art
The following Unites States patents and the patents cited therein are known to exist:
______________________________________ 2,014,800 2,838,179 2,860,787 2,980,257 3,460,679 3,840,045 4,052,312 4,218,320 4,450,075 4,629,558 4,705,626 4,826,059 4,894,153 5,078,871 ______________________________________
Also known to exist are British patent 557,214 and German patent 478,770.
In general, these prior art patents disclose the broad concept of utilizing magnets in various specific structures and applications for "capturing" magnetizable metal particles too small to be "captured" by conventional filter elements.
While numerous prior art patents have been issued embodying the concept noted in the preceding paragraph, none of the structures disclosed in these patents appear to be commercially successful. It is believed that one reason for the lack of success is the cost of manufacture of the conventional devices resulting from their particular mechanical design.
Accordingly, one of the important objects of the present invention is the provision of a magnetic filter strap that is inexpensive to manufacture and long-lasting in use.
Another disadvantage with some of the prior art devices is their inability to readily accommodate cannisters or containers of varying sizes. It is therefore another object of the present invention to provide a magnetic filter strap that is universally applicable to most oil filter cannisters or filter housings or conduits, including large diesel engine filters and smaller automotive lubricating oil filters.
The relative difficulty of applying the magnetic filter structures of the prior art is believed to be another reason for the lack of successful commercial exploitation of many of the prior art devices. U.S. Pat. No. 4,894,153 for a magnetic attachment for a filter exemplifies such difficulty in that the connecting links engaging the top rim would interfere with the sealing ring at the top of the filter on many models of "spin-on" filters, rendering the device inapplicable to many models of filters, particularly on replaceable cartridge type oil filters that do not possess a top rim bead to clip to.
Accordingly, a still further object of the present invention is the provision of a magnetic filter strap for universal application to all types of filter cannisters or housings or conduits through which pass liquids, fluids or particulate materials such as grains and grain flakes of various kinds and in which may be entrained magnetizable metallic particles.
It is noted that many of the prior art devices utilize magnetizable metallic clamps or clips for attachment of the filter devices. The use of such magnetizable material as a support for the permanent magnets tends to weaken the effectiveness of the magnetic fields produced by the magnets for the reason that such materials tend to "short circuit" or concentrate the magnetic field in a location outside the cannister or filter housing, thus reducing its effectiveness within the housing or cannister, and reducing the ability to attract magnetizable metallic particles suspended in the liquid within the filter housing, or magnetizable metallic particles flowing in a stream of air or a stream of particulate material.
Accordingly, yet another object of the invention is the provision of a magnetic filter strap that maximizes the strength of the magnetic field within the oil or liquid filter housing or conduit so as to impose on the magnetizable metal particles suspended in the liquid, or passing through the conduit, a maximum attraction force so as to extract the magnetizable metal particles from the flowing body of liquid, fluid or particulate material, and collect and retain them in a localized position on the interior surface of the conduit or housing wall until they are removed therefrom during cleaning of the conduit or housing.
It is also noted that some of the prior art devices are themselves immersed within the body of flowing liquid, with the expectation that the metallic particles suspended in the liquid flowing around the magnets will adhere to the magnets and thus be extracted from the body of flowing liquid. The disadvantage of this arrangement is that space between the cannister or housing and the filter element contained therein is limited, and the intrusion of the magnetic device within the cannister or housing causes an obstruction that prevents the free flow of the liquid. Accordingly, a still further object of the invention is the provision of a magnetic strap that may be detachably applied to the exterior of a cannister or housing or conduit through which flows a body of fluid or particulate material that may contain magnetizable metallic particles suspended therein, all without obstructing the passage of the fluid, or liquid, or particulate material past the magnetic strap.
Yet another object of the invention is the provision of a flexible magnetic strap adapted to be fabricated of indeterminate length and having attachment means at opposite ends of the strap to enable engagement of the end portions of the strap to each other or to adjacent associated portions of the strap to effectively retain the magnetic strap wrapped about an elongated detachable conduit section or insert sealingly disposed between the associated ends of a longer conduit of indeterminate length.
Because the magnetic strap of the invention will sometimes be utilized in environments in which there is present a great deal of vibration, it is an advantage to form the strap in a manner that it may be tightly wound about a supporting cannister, housing or conduit with the magnets contiguous to the outer surface of these supporting members. Accordingly, another object of the invention is the provision of a magnetic strap that is constructed of elongated elastic material with the magnets embedded in the elastic material so that adjacent magnets present poles of opposite polarity, and which incorporates attachment means at opposite ends to retain the flexible and elastic magnetic strap in elastically stretched condition on the supporting structure.
A still further object of the invention is the provision of a supporting strap and multiple magnet assembly that is light in weight, inexpensive to fabricate, and extremely flexible to enable the strap to be wrapped about or supported on or by cylindrical or non-cylindrical supporting cannisters, housings or conduits through which flow liquids, fluids, or other particulate materials believed to contain suspended or entrained magnetizable metallic particles.
The invention possesses other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and the drawings. It is to be understood however that the invention is not limited to the embodiments illustrated and described since it may be embodied in various forms within the scope of the appended claims.